With the mobile communication technologies and processor technologies dramatically evolved, electronic devices (e.g., mobile terminal devices) today may perform a variety of functions beyond a traditional call function. For example, various applications such as Internet browsers, games and calculators have been developed for and used in the electronic devices. As various functions have become available in the electronic devices, security for information stored in the electronic devices has become more important. In response to security needs, authentication techniques based on user's biometric information have been developed.
Authentication techniques based on biometric information may include processes of acquiring biometric information regarding, e.g., a fingerprint, an iris, a voice, a face, a blood vessel, etc. from a user and comparing the acquired biometric information with previously registered biometric information to determine whether the user is an authenticated user. In particular, fingerprint recognition technology is most commercially available for some reasons such as convenience, security, and economy. For user authentication using fingerprint recognition, the electronic device stores fingerprint information extracted from a user's fingerprint image in a memory thereof. Then, when any fingerprint image is newly input from a user who requests authentication, the electronic device compares fingerprint information extracted from the fingerprint image input with the stored (i.e., registered) fingerprint information. If the fingerprint input is identical with the stored fingerprint, the electronic device authenticates the user as a registered user.
If the size of a fingerprint sensor is smaller than the size of a user's actual fingerprint, the fingerprint sensor fails to scan the user's entire fingerprint region by one touch. If the electronic device acquires only a partial fingerprint in a fingerprint registration process, the rate of fingerprint recognition is inevitably lowered at the fingerprint authentication.
In other words, the quantity of fingerprint information acquired at a time by the fingerprint sensor is considerably small in view of the actual size of a user's fingerprint. Therefore, in order to acquire the entire fingerprint information from different positions for recognition, the fingerprint sensor requires several times of fingerprint inputs or the movement of a user's finger recognizes. However, it is not easy to accurately detect or predict unregistered regions of a fingerprint.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.